ISCHNOCHITON. 75 



Lophyriscus THIELE, t. c., p. 377, for textilis and oniscus. 



Beanella THIELE (not Dall !) t. c., p. 388 for rissoi Payr. and 

 cajetana Poli ! 



Dr. Thiele has added a considerable number of synonyms to this 

 genus. His group Radsiella consists of small subtypical Ischno- 

 chitons and one true Chiton (capensis). His Stereoplax is founded 

 upon the type of the Ischnoid section Iscknoplax Cpr. (see Vol. XIV, 

 p. 64, 65) ; and he has placed the same species under another name 

 in his " Stenoplax." He fails completely to understand the true 

 characters of Stenoplax Cpr., including Lepidozonas only under that 

 name. Rhodoplax contains two small species of Ischnocliiton. 

 Beanella is an odd compound of Ischnochiton and the type of Lepid- 

 opleurus. The true Beanella belongs to Nuttallina, q. v. 



I. PURPURASCENS C. B. Ad. (Vol. XIV, p. 58.) 



Has been collected at Bermuda by Goode, I am informed by 

 Dr. W. H. Dall. 



I. RADIANS Cpr. PL 16, figs. 48, 49. 



Shell oval, rather depressed, carinated, the side-slopes straight. 

 Surface lusterless. Color olive-purplish, radially streaked with whitish 

 dashes or flames, having some purple patches, and on the diagonal 

 line a few snow white spots ; ridge of valves purple or white. 



Median valves smooth to the naked eye, the lateral areas indis- 

 tinct, not raised, having a few subobsolete radial riblets. Entire sur- 

 face of all valves evenly, densely and most minutely granulated. End 

 valves having narrow, low, indistinct, numerous radial riblets hardly 

 visible except toward the periphery. Mucro in front of the middle, 

 moderately prominent ; the posterior valve being shaped as in /. 

 retiporosus. 



Interior dark blue. Anterior valve having 10, central valves 1-1, 

 posterior valve 10 slits. Sinus squared, the sutural-plates not con- 

 tinued across it. 



Girdle speckled, densely covered with shining, rather weakly 

 striated convex scales measuring about i or \ of a mill, in width. 



Gill row as long as the foot. 



Length about 12, breadth 7 mill.; divergence 120. 



Monterey, (jal. ; San Pedro (Cooper.) 



The original description will be found on p. 121 of vol. xiv. Car- 

 penter's type was from Monterey, and was a larger specimen than 

 that here figured and described, which is Mus. Smiths. Inst., 19470. 



